Clamp attachment



May 15, 1928. 7 1,669,443

E. q. BILLSTROM CLAMP ATTACHMENT Filed Jan. 1927 AAI Ill 17 Patented May 15, 1928.

UNITED STATES EDWIN J. BILLSTROM, OF ROCKFORD, ILLINOIS.

CLAMP ATTACHMENT.

Application filed January 5, 1927. Serial No. 159,087.

,-. This invention relates to a novel attach- :tfor clamps, such as are used in wood w snag ferthe holding of work after the gluing thereof, and has for its principal object the provision of attachments .in the iature of auxiliary jaws to increase the range of sizes of work which can be accommodated by the clamp and insure uniform clamping pressure irrespective of the size orshape of the work.

According to the present invention auxiliary jaws are provided for application to the )rdinary jaws of a clamp, such as are used for bench or machine work, and may be set at different heights depending on the size of the work to be handled so as to locate the center line of pressure between the jaws approximately midway of the height of the work and thereby secure practically uniform distribution of pressure and correspondingly improve the grade of work produced. The auxiliary jaws are, furthermore, conformed m their rear if aces to reckon the main jaws so as to be tiltable and accommodate the clamp to the particular shape of the work being handledand permit even pressure on the work. In the present embodiment of my invention the holding means for the auxiliary jaws comprises .yieldable leaf springs clipping over the main jaws and bearing against the rear faces thereof, the rocking of the auxiliary jaws being permittedby the yielding of the leaf springs when the auxiliary jaws are caused to be tilted by the work.

The invention is more fully described in the following specification in which reference is made to the accompanying drawing where- .in'

Figure 1 is a side view of a standard type )f bar clamp having the jaws thereof aquipped with the novel attachments of my invention i v Fig. 2 is a horizontal section taken on the ine 2-2 of Fig. 1 and illustrating both the manner of application of the auxiliary jaws to the main jaws and the capacityof the auxiliary jaws for rocking sidewise;

Fig. 3 is a vertical section taken on the line 3-3 of Fig. 2 and serving to show the capacity of the auxiliary jaws for rocking vertically; and j Fig. 4 is a rear face view of one of the auxiliary jaws removed from the clamp.

The same reference numerals are applied to corresponding parts throughout the views.

Any suitable or preferred type of bar clamp would serve to show the manner of application of the present invention. The bar clamp shown in Fig. 1 is of a standard well known type and so far as the present invention is concerned maybe used for bench work or on a glue clamp carrier machine. It comprises a bar 5 having a fixed jaw 6 and a movable jaw 7 mounted thereon, the latter being operated by a slotted rod 8 in relation to which it is adjustable endwise of the bar 5 by engaging the spring pressed latch 9 selectively in any one of the spaced slots 10. The rod 8 is operated in the usual manner bythe screw 11 and handled nut 12 so as to clamp work between the jawsfi and 7 after the gluing thereof. It has been found that a clamp of this kind has a rather limited range of usefulness inasmuch as certain sizes of work will overreach the jaws to such an extent that it is impossible to secure uniform distribution of pressure. Furthermore, the work to be handled had to be of a perfectly uniform shape inasmuch as the jaws were rigid and incapable of adapting themselves to the irregularities of the work. It is, therefore, the principal object of my invention to provide attachments for the clamping jaws in the nature of auxiliary jaws to surmount the main jaws and be adjustable above the height thereof and correspondingly increase the ca acity of the clamp as respects the height of the work that may be handled, the object being to adjust the auxiliary aws vertically depending on the height of the work so as to have the center line of pressure between the clamping jaws approximately midway of the height of the work and thereby insure uniform distribution of pressure. It isra still further ob ject of the invention to provide auxiliary jaws attachable in the manner referred to and capable of rocking in any direction on the main jaws so as to accommodate themselves to the irregularities of the work.

The auxiliary jaws are shown at 13, and inasmuch as they are substantially identical a description of one will suffice for both. These jaws surmount the main jaws 6 and 7 in front of the clamping faces thereof in the manner most clearly shown in Figs. 2 and 3. Each auxiliary aw has side flanges let serving to hold the same against lateral displacement from the main jaw'and has a pair of leaf springs 15 fixed to the upper end on the rear face thereof, as at 16, to

clip over thctopbf the main jaw and serve as yielding holding means permitting easy adjustment of the auxiliary jaw vertically relative to the main jaw; The lot-er endof the auxiliary jaw is cut out as shown at 17 (Fig. i to'straddle the bar 5 when the auxiliary jaw is in its lowermost position substantially as shown in Fig. 1. It will be noted that the free ends of the lead springs 15 are bent outwardly, as indicated at 18,;so as to pass freely-over theuppcr end 01' the main aw when the auxiliary jaw being applied. The leaf springs are provided of such a length thi'ltj lille ends 18 are disposed approximately midway between the upper and lower ends of the jaw. The p ur pose in this is to have the auxiliary JELW properly secured on the niain jaw in every state of ad ustment. thereo't. The rear face of the auxiliaryj aw is so conformed that the auxiliaryjaw is capable of rocking in any direct on on the front or clamp ng face of thernain aw. It will benoted in Figs. 2

and 2'} that the auxiliary is of greatest,

thickness substantially atjthe center thereof so as to have a high point at 1 9 from which point all portions of therear face are in.- clined. In other words, the rear lace oi the auxiliary jaw is convex orarcuate in all direotions. The high point l?) is therefore,

approximately in line with the lt'ree ends 18 of the leaf springs 15. TheauXiliary jaws are thus perfectly free to rock vertically with respectto the main jaws and such movement thereof will not result in a deflection of theleaf springs 15. Lateral or sidewise rocking ofthe auxiliaryjaws wilL-however, necessitate some deflection oft the leaf springs. In other words, the'auxiliary jaws are universally tiltable relative to the main jaws. i

In operation the auxiliary jawsarejboth adjusted vertically in relation to the bar 5 depending on theheight of theworklto be handled. The QCljUSUDQDtdS finadeprefer ably with a view to; having the high point 19, which isat the centerof the a'u 'iliary jaws, approxin'iately midway of the [height of the work so thatthe center line of pres-- sure will be properly situated witl lrespect to the work and substantially uniform distribution of the clamping pressure will result. The capacity of the auxiliary jaws to rock on the main jaws permits them to assume. positions inclined in any direction as required by the particular shape ofthe work being handled. The tilting oi the auxiliary jaws coupled with the fact thatthe center lineo-l pressure is substantially midway of theheight ofjthe work dnetothe acljustn'lent ot the auxiliary jaws greatly improves the character olf the work produced. Itis also believed apparent from the foregoing descriptionthat the auitiliary jaws are readily attachable and detachable 'well as adjustable due to the p ovisi'on of thesiinple type of frictional holding means. i

It is believed that the foregoing description conveys a clear understanding of the invention and of its purposes and advantages that anyone skilled in the art to which the invent relates will readily appreciate the possible uses and applications thereof.

1. In a clamp in front of the clamping face the and adjustable in a plane parallel theiim thendwise of the main jaw, said auxiliary jaw having lateral rearwandly directed-ham is 1, extending endwise of the sides thereof to be disposed along the sides of the main jaw to guide the auxiliary jaw in iitsad ustrnent, and spring means mounted on said auxiliary jaw and engaging the back of the main jaw to holdthe auxil ary yieldingly posi tion of adjustment. 2. In a clamp as rear facebetween the lateral fl nges .to 1'0- v de a rocker surface p'eri'in'ttlng tl 1'- iary jaw to be inclined in any direction re a.-

set for-ta in claiiifr l the provision on said auxiliary o li convex having. a clamping pie senting a flat face for engagement with the work to be clamped, an auxiliary clamping jaw rcn ovablymounted on the main jaw tiveto the clampingface at the main jaw,

thesaid lateral anges serving to. hold the auxiliary jaw in iilace in any position tl l' leof and the spring means being arranged to] yield to permitthe turningthereof. i V 3. In a olamp as Set forth in Clalfil 1 are provision on said auxiliary j aw of a c'onyex rear face between the lateral flanges to pro- I vide "rocker surface permitting the au tiliar'y jaw to be inclined ma y direction re a;- tive to the lamping face of the .n ain jaw, the said lateral flanges serving to hold the auKila-ry aw in place in any positi'ontlier'eof, the high point of the convex rear time being approxiniately centrally located, and

the said spring means being arranged to engage the main jaw at point in line with thesaid high point of the convex rear fade substantially anchfor' the purpose .tlescribed.

'- 4. In a claim having a clamping jaw i senting a flat face for engagement withlthe guide theauxiliary jaw in its adjustment,

anda pair of'leaffsprings mounted on said auxiliary aw and extending endwise of the rear ffacefthereolt. alongside said flanges to clip over the topot the nrai n' jaw towho'ld the auxiliary jaw yieldingly in any position of adjustment. A

5. In a clamp as set forth in claim 4, the provision on said auxiliary jaw of a convex rear face between the side flanges arranged to provide a rocker surface whereby the auxiliary jaw may be inclined in any direction relative to the clamping face of the main jaw, the said side flanges serving to hold the auxiliary jaw in place in any position thereof, and said leaf springs being arranged to yield to permit the tilting thereof.

6. In a clamp as set forth in claim 4, the provision on said auxiliary jaw of a convex rear face between the side flanges arranged 15 to provide a rocker surface whereby the auxiliary may be inclined in any direction relative to the clamping face of the main jaw, the said leaf springs being secured at one end of the auxiliary jaw and extending approximately to' the middle thereof in line with the high point of the convex' rear face substantially as and for the purpose described.

In witness of the foregoing I afi'ix my signature.

EDWIN J. BILLSTROM.

kiwi- Mm...

CERTIFICATE oF CORRECTION.

Patent No. 1,669,443. Granted May 15, 1928, w

EDWIN J. BILLSTROM.

It is hereby certified that error appears in the printed specification. of the above numbered patent requiring correction as follows; Page 2, [ice 116, claim 4, for the word "claim" read "clamp"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 19th day of June, A. D. 1928.

M. J. Moore,

(Seal) Acting Commissioner of Patents. 

